One of engineered woods, glued laminated timber (GLT), can provide a constant level of performance and desired strength even if the quality of wood is low. Due to this fact, there is a growing interest in GLT using domestic species and related research has been carried out continuously. In addition, GLT is popularly being applied to the long-span or high-rise structures overseas. However, KBC 2016 does not allow the engineered woods to be used for middle and high-rise buildings by limiting height. Therefore, a proper design procedure and rationale should be clearly presented by the help of performance-based seismic design. With this background, the goal of this study is to establish a specific procedure for design of a 9-story building with RC shear walls and GLT frames according to the performance-based design of KBC 2016. The performance objectives were set according to KBC and the acceptance criteria for each goal were defined. The RC shear walls and GLT frames were designed by concrete and wood structure requirements, respectively. Analytical models were developed to reflect their nonlinear features, and both nonlinear static and dynamic analyses were conducted. Performance evaluation results showed that the shear walls have insufficient shear strength, so they were re-designed. Consequently, it has been confirmed that GLT frames can be applied to a 9-story office building with the assistance of RC shear walls and performance-based seismic design.

대형선박의 발전에 사용되는 증기터빈에는 핵심부품으로서 노즐플레이트가 활용되는데 정밀 산업 이 발전한 요즘에도 오래 전의 설계와 생산방식을 답습하고 있다. 노즐플레이트는 많은 터빈 블레이드와 이너링, 아우터링으로 구성되어 있고 이들을 서로 용접하여 제작한다. 용접 시에 블레이드의 뒤틀림 등으로 인하여 그 용접위치에 약간의 변위가 발생하여 각 블레이드 간의 pitch가 불균일하여지고 이로 인해 플레이트의 성능 저하가 우려된다. 이러한 점을 개선하기 위해 용접식 보다는 pitch의 등간격을 유지시키는데 유리한 조립식 설계로 전환하는 것이 필요하다. 이는 설계 변경을 해야 하며 또한 새로운 설계 시에 그에 대한 응력을 기초로 하는 구조해석과 장시간 사용되었을 경우에 대비하여 내구성 시험이 수반되어야 한다. 본 연구는 터빈 블레이드의 구조 설계를 조립식으로 변경하고 이의 결합성을 검토한 후 사이버 공간상에서 안전성 검증을 통하여 실용 가능성을 입증하고자 한다.

Many studies can now confirm that the body growth of youths aged 6 to 17 is increasing due to changes in dietary habits and lifestyles in Korea. If the growth of youths increase continuously, many companies that make chairs for youths must prepare anything. Youth's chairs, which are being produced at present companies, are produced by companies with multiple data. Looking at this chair, it may not fit the body of youths of the future. It is necessary to change the design dimension of the chair for that. In this research, we try to predict how the body of youths in the future will become bigger by using physical data of youths aged 6 to 17 years old. Then, using the predicted physical data, we will propose the dimensions of the design of the chair for youth.

기후변화에 따른 영향으로 전 세계적으로 물부족 문제는 지속적으로 증가할 것으로 예상된다. 이러한 물부족 문제를 해결하기 위하여 다양한 대체수자원 확보기술이 개발되고 있으며, 그 중에 해수담수화 기술이 가장 활발하게 도입되고 있다. 최근 새로운 개념의 해수담수화 기술이 검토되고 있으며, 그 중 막증발법(Membrane distillation, MD) 기술이 활발하게 연구되고 있다. 국토교통부 국가연구개발사업으로 진행 중인 “Global MVP 연구단”에서는 세계 최대 규모인 400 m³/일 규모의 복합탈염 플랜트를 구축하고 있으며, 국산 중공사 막증발 모듈을 이용하여 새로운 개념의 복합탈염 설계기술과 구축기술을 확보하고자 현재 다양한 연구를 진행 중에 있다.

일반적으로 SWRO의 경우 에너지 소비량은 3.5 kWh/m³ 이상의 에너지를 소비한다. 그중 RO트레인은 2.5～3.0 kWh/m³를 소모해 전체 에너지 소비량의 70% 이상을 소비하고 있으며, 전체 시스템 에너지 절감을 위해서는 RO트레인의 최적 설계가 중요하다. 따라서 당사는 다양한 RO트레인의 설계를 최적화 하여 소모되는 에너지의 양을 10% 절감하고자 한다. 1) ISDInternally Staged Desing)을 적용한 1st Pass의 설계최적화, 2) SPSP(Split Partial Sencond Pass) 적용을 통한 2nd 용량 최적화 설계, 3) 초고성능 막을 적용한 Single Pass 설계방법의 최적 조합을 통해 저에너지 역삼투막 시스템 설계 기술을 개발하고자 한다.

Membrane-based gas separation process is one of the next generations’ gas separation processes for carbon capture and storage (CCS). Membrane process has the advantages of i) low energy consumption without a phase change during the separation, ii) small footprint and easy scale-up of membrane modules, and iii) clean process without any emission of harmful byproducts. The hollow fiber membranes used in this study shows CO2 permeance over 900 GPU (1 GPU = 10-6 cm³/cm²⋅sec⋅cmHg). Using the hollow fiber membranes and modules, we established a moveable CO2 separation system including pretreatment of flue gas and 3-stages of membrane cascade. The system was installed at the several on-site flue gas sources, and the performance of pilot plant operation will be presented in the presentation.

This paper describes a preliminary ship design optimal design method in the process of hull form design. In the deterministic approach, an interdisciplinary ship design method integrates principal dimension decisions and hull form variations in the preliminary ship design stage. Integrated ship design, as presented in this paper, has the distinctive feature that these parameters are evaluated simultaneously. Conversely, in sequential design, which is based on the traditional preliminary ship design process, hull form designs and principal dimension decisions are determined separately and sequentially. The current study adopts the first method to enhance the design quality in the early design stage.

The various hydraulic equipments including main control valves are composed of relatively long replacement parts, so the stability is very important. These systems ensure system safety by not delivering pressure to actuators when pressure exceeds the limiting pressure. According to various hydraulic equipments, the required pressure of every hydraulic actuators are differenced. So the optimal design of the main valve is indeed needed. In the previous study, the detail shapes and the boundary conditions of the main control valve were studied by CFD analysis using FLUENT. Based on the previous study, the optimal design of the main control valve is done by applying the parametric modeling technique and then the optimum design of the main control valve is investigated by CFD analysis.

Recently, the robotic hand sector is widely utilized throughout the entire machine industry, where gripping mechanism is gradually becoming more complex and standardized. In this study, studies were conducted to hold irregular, unstructured objects with simpler, more manageable operating principles based on compliant mechanics. In fact, it used the principle of buckling which is not commonly used in mechanical design to provide stable grasping force without giving any damage to objects with uncertain magnitude and rigidity. By using CFM(constant force mechanism) based on the principle of buckling, the force of the object and the contact surface is fixed evenly across the segments, providing a stable grasping force to the object. Also, a bar that serves as a linear guide prevents the hand from buckling to unwanted direction gives elaboration to the hand. With a simpler principle, the lower unit price and higher applicability, there is little friction in the mechanism, and it focused on creating a lightweight hand, which have significance for about 90% of excellent gripping performance.

On November 15, 2017, Pohang earthquake occurred. Its local magnitude was announced to be ML=5.4 by Korea Meteorological Administration (KMA). Ground motion data recorded at KMA stations were obtained from their data bases. From the data, horizontal and vertical response spectra, and V/H ratio were calculated. The horizontal spectra were defined as GMRotI50 spectra. From the statistical analysis of the GMRotI50 spectra, a mean plus one standard deviation spectrum in lognormal distribution is obtained. Regression analysis is performed on this curve to determine the shape of spectrum including transition periods. Applying the same procedure, the shape and transition periods of vertical spectrum were obtained. These results were compared with the Korean standard design spectra, which were developed from domestic and overseas intra-plate earthquake records, and Gyeongju earthquake response spectra. The response spectra of Pohang earthquake were found to be almost identical with the newly proposed design spectra. Even the V/H ratios showed good agreement. These results confirmed that the method adopted when developing the standard design spectra were valid and the developed design spectra were reliable.

본 논문에서는 페이즈필드 설계법 기반의 피로 제약 조건 구조물의 위상최적설계를 수행하였다. 페이즈필드 설계법의 도입으로 기존의 위상최적설계법에서 발생하기 쉬운 중간 영역의 크기를 크게 감소시켰다. 수정된 upper bound P-norm의 도입으로 모든 지점의 응력 성분을 고려하면서, 전역적 응력값이 국부적 최대 응력값과 근사한 값을 가질 수 있도록 설정하였다. 또한 기존의 피로 파괴 제약 조건 위상최적설계에서 다루지 않았던 응력 수정 계수에 대한 고려를 위하여 위상최적설계 결과물의 1차 주응력 성분을 고려하여 응력 수정 계수를 도입하고 이에 따라 허용 응력 진폭 값을 수정 하였다. 이를 통하여 인장 응력으로 인한 내구 한도 감소 요인을 반영한 체계적인 설계 방안을 제시하였다.

Construction of irregular-shaped concrete structures requires a lot of time and money. To reduce the cost and time, the F3D(Free-Form Formwork 3D Printer) technology was adopted in manufacturing EPS(Expanded Polystyrene) formwork for irregular-shaped concrete structure. To design EPS formwork precisely, lateral pressure acting on irregular-shaped formwork and deformation of EPS form liner should be evaluated. However, in current Korean formwork standard, there are no standards for irregular-shaped formwork as it includes a lot of complex variables. For this reason, several researchers developed 3-dimensional finite element analysis model to calculate lateral pressure exerted by fresh concrete. In this study, deformation of irregular-shaped EPS formwork and lateral pressure acting on formwork was examined using finite element analysis model.

기존의 한방향 펌프는 순환과 배수를 위해 각각의 모터를 사용하지만, 양방향 펌프는 하나의 모터로 모터의 회전 방향에 따라 배수와 순환이 모두 가능하므로 원가절감이 가능하다. 하지만 양방향 펌프는 배수와 순환 시 펌프 케이싱 내부에서 역류와 흡입이 발생하여 유입된 물이 각각 배출구와 순환구로 원활하게 유출되지 못하는 단점이 있다. 본 연구에서는 주효과 분석을 통해 배출과 순환 시 유출되는 유량과 토크에 주요한 영향을 미치는 인자를 설계변수로 선택하여 실험계획법, 근사 모델, 그리고 최적설계를 통해 펌프 케이싱 형상을 최적화함으로써 역류와 흡입은 개선하고 펌프의 토크 대비 배출구와 순환구의 유량을 증가시키는 효과를 거두었다.

PURPOSES : This study aims to survey and analyze the status of the design and completion documents output delivery system in public construction projects in order to assess the problems of the Ministry of Land, Infrastructure and Transport (MOLIT)'s electronic delivery system, with a focus on roads and rivers, and to offer improvement measures. METHODS: This study first surveys and analyzes laws and existing study trends with regard to the design and completion documents output delivery system in public construction projects. It further analyzes the status of the output delivery system in public construction projects, including roads, rivers, expressways, water resources, and railroads. In addition, a comparative analysis of the current electronic delivery system of MOLIT and Korea Expressway Corporation in the road field is conducted, and the problems and improvement measures for MOLIT's electronic output delivery system are presented. This study seeks to analyze problems and prepare improvement measures with regard to road and river public construction projects, as ordered by MOLIT’s five regional offices. RESULTS: This study sought to prepare the electronic output delivery system with regard to public construction projects and present the analysis of its major problems and improvement measures in four categories: “the preparation of electronic design documents output delivery system improvement measures including inspection and delivery,”“preparation of guidelines, systems, etc., concerning electronic design documents,”“preparation of improvement measures for the construction project management system and electronic design document support tools”, and “linking of MOLIT's electronic output delivery system with relevant agencies and the expansion thereof to local governments.” CONCLUSIONS : This study analyzed the current status and problems of the MOLIT's electronic output delivery system in the field of road and river construction projects, and presented corresponding improvement measures. This study is expected to address the problems of the MOLIT's electronic output delivery system, and to provide the foundation for the preparation of an efficient electronic output delivery system for design and completion documents. In addition, this study is expected to boost the quality and utilization of the electronic design documents output, and to exchange, share, and link construction information among relevant agencies so as to prepare the foundation for sharing construction information.

The purpose of this study is to compare and evaluate the safety of the facility using the Abaqus finite element analysis program according to the material characteristics like steel and GFRP.